Merge remote-tracking branch 'origin/master' into feature/ipv6_support

.gitignore

protocols/bgp/packet/BUILD.bazel

protocols/bgp/packet/bgp.go

protocols/bgp/packet/decoder.go

protocols/bgp/packet/decoder_test.go

protocols/bgp/packet/encoder.go

protocols/bgp/packet/nlri.go

protocols/bgp/packet/nlri_test.go

protocols/bgp/packet/path_attributes.go

protocols/bgp/packet/path_attributes_test.go

protocols/bgp/packet/update.go

protocols/bgp/server/BUILD.bazel

protocols/bgp/server/fsm.go

protocols/bgp/server/fsm_established.go

protocols/bgp/server/fsm_established_test.go

protocols/bgp/server/fsm_open_sent.go

protocols/bgp/server/fsm_test.go

protocols/bgp/server/update_helper.go

protocols/bgp/server/update_helper_test.go

protocols/bgp/server/update_sender.go